Many different types of studded plates which may be used as supporting plates are known. They may be used as ordinary supporting plates, drainage plates, decoupling plates, or plaster plates for plastering or support for adhesive for tiles for example when flooring with ceramic tiles.
All concrete floors resting on the ground contain moisture. Floor coverings such as wooden floors can therefore not be placed directly on the concrete. Many years may be needed to dry out a concrete floor placed on the ground. The floor may also be affected by rising damp. Initially, all concrete floors contain residual moisture and the above problem therefore concerns cellars, basement floors, slab on ground floors and floor between different storeys of different types of concrete, including for example floors made of light expanded clay aggregate concrete and lightweight concrete. The moisture in the concrete is often invisible and difficult to detect. This results in an unawareness of the risks such as rot, moisture damage etc. Without an effective damp proof membrane with sufficient performance characteristics, moisture from the concrete will for example attack wood materials from underneath. The same problem also concerns tiled floors wherein the filled joints will allow passage of moisture.
The result is damaged floors with cracks, mould and rot. In addition, hazardous mould spores, bad smell and a poor in-door environment may result.
The same effect may arise on concrete walls, as in floors, and contain or be affected by rising damp, especially basements with below ground walls.
To solve this problem, studded plates are used for most problems related to moisture in cellars providing “passive” venting towards the room. The studded plates often comprise hollow studs with circular or rounded cross-section, i.e. the form of the circumference of the studs, with a height from 3 to 5 mm. The studs are often distributed in a diamond pattern or a check-board pattern providing adequate distribution of the loading as well as venting. The studded plates are places with the top of the studs facing downwards toward the base floor to obtain an air gap on the underside of the plate, between the studs.
The plates may be joined by sealing tape on the topside of the plates to obtain a sealed floor. In case of severe problems with moisture, smell or other emissions, the air gap beneath the studded plates may be ventilated mechanically in order to provide air flow over the concrete plate and create a negative pressure in relation to the room. A ventilated air gap may also contribute in the drying out of the concrete.
Recently, plates have been developed comprising studs with undercuts or overhangs, meaning that the area of the opening of a stud is smaller than the area of the top of the stud, giving a good anchoring of plaster or adhesive, independent of which face the plaster or adhesive is applied. Such a plate is described in EP 1 068 413 issued on Aug. 10, 2004 to Isola AS for example.
The studs in the above mentioned patent are characterized by a uniform shape of the studs which are distributed on the plate in a repeated pattern. The pattern often allows folding of the plate in the longitudinal and/or transverse direction of the plate, but also in a 45° angle.
However, it is a problem with the above mentioned solution that a plate placed on the floor should be turned up against the wall of the room, in order to guide the humid air out of the air gap. In other words, the air gap must be in contact with the room. In the simplest manner, this is achieved by folding the plate at the transition between the floor and the wall. The problem with this solution is that all the above mentioned plates thereby obtain a folding crease which either inhibits the transport of humid air or for example the plate comes in direct contact with the adhesive used against the floor thereby blocking the air gap.
It is also quite usual to laminate the studded plate with a fabric or a grid on the top of the studs in order to bond the plate temporarily or permanently to the concrete floor, so that the plate is evenly fixed to the substrate during installation of the floor covering or tiles. The fabric, which will be applied with adhesive, will also contribute in blocking the transport of air as it will be stretched against the folding crease of the plate and thereby block the air gap.
One solution to this problem has been to place the plate on the floor at a small distance from the wall and to use a special edge plate which is bonded onto the top face at the edge of the plate on the floor, to finish the venting towards the room. However, there is always a risk that plates on the floor are pushed towards the wall and will remain in contact with the wall, or that adhesive is pressed into the junction between the floor and the wall, thereby blocking the venting.
The present invention is aimed at solving the above problems and to provide a plate and a method for placing it so that transport of moisture is secured away from the substrate, such as a floor, in a simple and sure manner.